There are two main devices for supplying and exhausting gases from the airways of a patient, for example, during a general anaesthesia procedure in surgery, they are the endotracheal cannula and the laryngeal mask.
The endotracheal cannulas are artificial airways used for maintaining permeable the upper airways and avoiding the tongue obstructs the airways, then adequate ventilation and oxygenation is provided to the patient while secretions of the patient are controlled when tubing is applied to the patient. The endotracheal cannula is a tube that is introduced to the mouth or the trachea avoiding the closing of the last and maintaining the ventilation or breathing of the patient, the endotracheal cannula is used when the airways are handled in short times. The neonates with respiratory difficulties require mechanic-ventilatory medical assistance through the endotracheal tube; so that, it is very important to have in mind the position of the endotracheal tube.
On the other hand, the laryngeal mask is used for controlling airways in adults and children under difficult situations of the airways as well as in different anaesthetic and surgical procedures. The laryngeal mask consists of a silicon tube connected at a 30° angle to a rubber mask that is slightly concave and has an inflatable rubber balloon.
The laryngeal mask has the advantage of being best tolerated in lower levels of anaesthesia in comparison with the endotracheal cannula; in addition the laryngeal mask causes fewer traumatic risks such as laryngeal pain and post operatory aphonia.
From the above, it is very desirable that the means that supplies and exhausts the gases from the airways of the patient remain unmovable with respect to the anatomy of the patient when the tubes are placed in the patient during an urgent surgical operation is carried out, or, in cases when artificial breathing is required for the patient when the same is on bed. Moreover, the patient requires certain liberty of movement and it is necessary avoiding the conducts to be obstructed in order to facilitate the breathing of the patient. In this regard, during the placement of the endotracheal cannula or the laryngeal mask, the same are usually inserted through the mouth of the patient, so that it is very important keeping the endotracheal cannula or the laryngeal mask fastened all the necessary time.
In the prior art, there are some devices for holding a cannula, which have been designed for holding the endotracheal cannula to the anatomy of a patient, one prior art device is disclosed in U.S. Pat. No. 2,908,269, this patent refers to a device for fixing the endotracheal cannula comprising a bite block which is inserted in the mouth in order to keep the jaws spread apart in a sufficient distance to permit the insertion of a resilient tube into the mouth and down the throat or trachea, depending upon the particular needs, without it being necessary to disturb the position of the bite block in the month during either insertion or removal of the resilient tube. Even though that this device is fixed in the mouth of a patient, wherein the cannula may be inserted or removed of the mouth without changing the position of said holder, the diameter of the cannula which is held in the device of this patent is limited to only one diameter, it is not possible varying the dimension of the aperture for holding cannulas with a different diameter according to the size of the user, in addition, the device has grooves and holes between the mouth and the plate of the holder in which biological material may be accumulated infecting the patient.
On the other hand, U.S. Pat. No. 4,249,529 discloses an endotracheal tube holder having a body which is secured by a pair of non-stretchable, head encircling straps to overlie the patient's mouth and portions of the cheeks. The straps, which are adapted to extend, one above and the other below, the patient's ears, have one-way tightening adjustability by pawl action. The body is integrally moulded to incorporate a quick-acting clamp having three integral hinges, one hinge pivotally connecting a pair of jaws of the clamp and the other two hinges supporting the jaws from resilient arms for snap-action between open and closed positions. The clamp is operative to secure or release the endotracheal tube while the straps retain the body in position on the mouth against dislodgment. Nevertheless the object of this device is facilitating the access to the mouth of the patient with an endotracheal cannula to be fixed, the device fails to provide a aperture with variable dimension, so that the device is only used when it is available an endotracheal cannula with a specific diameter for this device.
Likewise, in the prior art, it is found U.S. Pat. No. 5,320,097 disclosing an endotracheal tube holding and securing device, which includes two identical hook-shaped members forming a “C” shaped gripper used for holding the endotracheal tube. Each hook-shaped member comprises a groove and a pin that allow longitudinal displacement of one member with respect to the other, thus varying the diameter of the “C” shaped gripper when there is a relative movement of one member to respect the other. Each of the hook members has straight an upper surface and a lower surface on which the lips of the user are positioned. In order to keep the holder it its original position, a fabric strap is provided in each of the ends of the hook members, the extension of the strap is adjusted to the diameter of the head of the user.
However, the holder disclosed in the previous paragraph fails to provide a textured surface in the inner part thereof in which the cannula may be in contact for reaching a firm holding thereof, so that unwanted displacements of the cannula may occur. In addition, when the holder is place, there is a possibility that one of the bolts remains jammed avoiding the relative movement between the members so that the use of the device is not possible any more. Another disadvantage of said holder is related with the fact that the size of the hooks is constant, in addition, the form of each hook is not ergonomic that provokes nuisance and lesions in the mouth of the patient that uses the holder.
Now, in US Patent Application 2008/0202529, it is disclosed an endotracheal tube holder including a base with a tube-securing block, the base is supported on the lips of the patient and is held to the head of the patient with the aid of bands. In order to maintain the cannula in place, a U-shaped clip is engaged in the block of the base. In addition, in order to avoid unwanted movements of the clip with respect to the block, both of them have edges provided with teeth which avoid said unwanted movement. In a further embodiment, said holder has an anti-bite block, which avoids teeth of the patient bite the cannula affecting the performance of the device. However, the holder of this patent application allocates the cannula at one side of the mouth of the patient increasing the risk of ulcerating the patient. Moreover, the holder has elements that are time-consuming when the holder is assembled, this means that the elements may not be placed at a first attempt; in addition the personal should have advanced skills for assembling the holder.
Other example of a cannula holder of the prior art is that known as the “Thomas” model endotracheal cannula holder fabricated by the company “Laerdal”, this model comprises an arc-shaped main body made from a rigid polymeric material having a central entrance by which the endotracheal cannula is introduced. In order to hold the cannula, this model uses a tightening screw that is located at one side of the arch, so that the screw should be rotated several times by the user in order to get a secure holding of the cannula. However, the cannula holder has the drawback that the screw pressures the cannula in order to maintain the same in place avoiding its movement; this mechanism may deform the cannula obstructing the air flow to the patient. Moreover, if the user that is placing the cannula holder in the mouth of the patient is not aware of the screw position with respect to the cannula, the last may be broken due to the concentration of axial forces at one point of the cannula.
From all the above previously disclosed, the holders of the prior art have surfaces that are in contact with the cannula that lacks of a textured surface to be held leading to an unsatisfying adjustment of the cannula to the patient. Moreover, the prior art devices fails to facilitate the cannula to be repositioned if the same is moved, on the other hand the comfort of the device is not taken into account, particularly when the holder is in contact with the skin or mucosa of the patient.